Having sworn their oaths to Emperor Alexius Comnenus, the Crusaders finally sailed across the Bosphorus River to Turkey. When they disembarked, however, there were no Turkish armies waiting for them. Unopposed, they marched to Nicaea, the capitol of the Sultanate of Rum, and laid siege to it. At last word reached the sultan, Kilij Arslan, who rode back to save his city (and his family) only to realize that this army of crusaders was much larger and better organized than the People's Crusade which had come before. They had not yet realized, however, that the city of Nicaea was being secretly resupplied by ships arriving by night from Lake Askania. Once they did, the Byzantines transported their own ships overland to blockade the lake and launch a coordinated assault with the crusaders to force the city to surrender. The crusaders marched towards Jerusalem, but along the way, the Turks launched a surprise assault on Bohemond's army. He ordered his knights to form a shield wall around the priests and civilians traveling with them, and they held for hours under a burning sun until reinforcements from the other crusading armies arrived. They rallied, defeated the Turks, and resumed their march.